- Email: [email protected]
Clinical Effect of Virtual Reality to Relieve Anxiety During Impacted Mandibular Third Molar Extraction Under Local Anesthesia
Journal Pre-proof Clinical effect of virtual reality to relieve anxiety during impacted mandibular third molar extraction under local anesthesia Yoshio Yamashita, PhD, DDS, Daiji Shimohira, PhD, DDS, Reona Aijima, PhD, DDS, Kesuke Mori, PhD, DDS, Atsushi Danjo, PhD, DDS PII:
S0278-2391(19)31343-6
DOI:
https://doi.org/10.1016/j.joms.2019.11.016
Reference:
YJOMS 58980
To appear in:
Journal of Oral and Maxillofacial Surgery
Received Date: 15 October 2019 Accepted Date: 7 November 2019
Please cite this article as: Yamashita Y, Shimohira D, Aijima R, Mori K, Danjo A, Clinical effect of virtual reality to relieve anxiety during impacted mandibular third molar extraction under local anesthesia, Journal of Oral and Maxillofacial Surgery (2019), doi: https://doi.org/10.1016/j.joms.2019.11.016. This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Published by Elsevier Inc on behalf of the American Association of Oral and Maxillofacial Surgeons
Clinical effect of virtual reality to relieve anxiety during impacted mandibular third molar extraction under local anesthesia
Yoshio Yamashita1, PhD, DDS; Daiji Shimohira2, PhD, DDS; Reona Aijima3, PhD, DDS; Kesuke Mori4, PhD, DDS; Atsushi Danjo5, PhD, DDS
1
Professor and Chief, Department of Oral and Maxillofacial Surgery, Faculty of Medicine,
Saga University 2-4
Research Associate, Department of Oral and Maxillofacial Surgery, Faculty of Medicine,
Saga University 5
Associate Professor, Department of Oral and Maxillofacial Surgery, Faculty of Medicine,
Saga University
Address correspondence to: Prof. Yoshio Yamashita, Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Saga University Nabeshima 5-1-1, Saga 849-8501, Japan Tel: 81-952-34-2397 Fax: 81-952-34-2044 E-mail: [email protected]
Abstract
Purpose: Many patients undergoing dental treatment have experienced pain associated with treatment, and they are anxious or fearful of treatment. Anxiety and fear have conventionally been dealt with by the use of inhalation anesthesia or tranquilizers, but their physical effects must also be considered, and they are not suitable for all patients. The purpose of this study was to assess the clinical effect of virtual reality (VR) to relieve anxiety during impacted mandibular third molar extraction under local anesthesia
Methods: We used VR to alleviate anxiety concerning surgical treatment in 51 patients undergoing impacted mandibular third molar extraction under local anesthesia. Fear and anxiety before and after treatment were evaluated by a questionnaire that included a visual analog scale (VAS). The post-treatment questionnaire asked patients to evaluate their satisfaction on a five level Likert scale. Heart rate variability (HRV) was also analyzed in the VR group using an acceleration plethysmograph (APG)
Results: Anxiety improved among patients who used VR (VR group), with a difference of –13.3 ± 28.7 mm in anxiety measured using a visual analog scale between before and during treatment, whereas it increased by 4.0 ± 22.3 mm in 49 patients who did not use VR. Furthermore, a post-treatment questionnaire using a five-point evaluation scale was administered to the VR group, and 92% reported that their anxiety had decreased. Objective evaluation by HRV measurement also showed a sympathetic nerve-predominant state before treatment, but during VR use during treatment, parasympathetic nervous activity was predominant, with a stable balance between the two. No patient showed symptoms suggestive of cybersickness.
1
Conclusions: These results demonstrate that VR may be valuable in dental treatment, particularly extractions, and surgical treatment.
Key words: Virtual Reality, Anxiety and Fear, Impacted Mandibular Third Molar Extraction, Heart Rate Variability
2
Introduction
The characteristic of orofacial pain is that it evokes subsequent fear and anxiety1. One of the best-known examples is dental treatment, which arouses anxiety and fear in many patients2,3. Analgesia with local anesthesia alone is insufficient to eliminate such anxiety and fear4. Sedation is frequently used for patients with dental phobia who are excessively anxious or frightened of treatment, involving intravenous anesthesia with propofol or a similar agent or inhalation anesthesia with nitrous oxide5. However, the use of drugs may involve restrictions on both patient and institution, and the scope for their use is limited.
Virtual reality (VR) refers to the techniques and systems used to create an environment by scientific and engineering techniques that is not itself a physical original but functions essentially in the same way by stimulating perception, including the user’s five senses. It consists of three elements: presence, autonomy, and interaction. It can therefore transport the user into a different experience by stimulating all the senses, not just sight. VR is already finding applications in a wide range of fields, and in medicine it is being put to use in areas including rehabilitation and medical education6,7. The use of VR for navigation in robot-assisted laparoscopic surgery has also recently been reported8. Studies have found that VR is effective for reducing pain and anxiety during surgical treatment9,10, but the details of this remain unclear. In this study, whether VR could be used to alleviate fear and anxiety while undergoing mandibular impacted third molar extraction under local anesthesia, the most common form of outpatient oral-maxillofacial surgery (OMS), was investigated.
Material and Methods
Study design 3
The study subjects were patients examined in the Department of Oral and Maxillofacial Surgery of Saga University Hospital in order to undergo mandibular impacted third molar extraction between April and November 2018. The patients were selected according to a number of criteria (Table 1). In particular, patients who suffered from motion sickness or claustrophobia and those with a history of cybersickness or vertigo were excluded from the study. The subjects were randomly divided into two groups, one that used VR (VR group) (n = 51 patients) and one that did not (non-VR group) (n = 49 patients). The characteristics of the patients in the two groups are shown in Table 2.
This study was approved by the Ethics Committee of the Faculty of Medicine of Saga University and was registered with UMIN Clinical Trials registry (UMIN000035594). Informed consent was obtained from all participants in this study. All methods were performed in accordance with relevant guidelines and regulations imposed by the IRB.
Subjective evaluation
Fear and anxiety before and after treatment were evaluated by a questionnaire that included a visual analog scale (VAS). Pain during treatment was also measured using a VAS. Anxiety was scored on a scale from “Completely relaxed” at 0 mm to “The most anxious state imaginable” at 100 mm. The post-treatment questionnaire asked patients to evaluate their satisfaction on a five level Likert scale with tooth extraction carried out while experiencing VR. They were also asked to evaluate the degree to which fear and anxiety were alleviated on a five-point scale. Other questions asked were whether they would want to use a VR device while undergoing further surgical treatment or during future dental treatment, and a section for free comments was also provided.
Objective evaluation 4
Heart rate variability (HRV) was also analyzed in 8 patients in the VR group using an acceleration plethysmograph (APG) (SA-3000Plus, TOKYOIKEN Co, Tokyo)11-13. The values measured in this study were the following: the low-frequency (LF) component (0.04–0.15 Hz), which reflects sympathetic and parasympathetic nervous activity; the high-frequency (HF) component (0.15–0.4 Hz), which reflects parasympathetic nervous activity; and LF/HF, which reflects autonomic nervous balance. These were measured twice, once before treatment and once 10 min after the start of the procedure. The measurement time was 3 min, and the patients were all placed in the supine position.
Surgical treatment
The impacted third molars were also horizontally impacted, corresponding to positions A and B and classes I and II in Pell and Gregory classification14.
After local infiltration anesthesia, patients
in the VR group were fitted with a biomonitor and a head-mounted display (OculusRift CV1, Oculus). Before the extraction was performed, they experienced a VR presentation for a short period and were asked to confirm that they were not feeling uncomfortable or disturbed. All extractions were carried out by a single specialist oral-maxillofacial surgeon. Had any patient been put off or made to feel uncomfortable by the VR, the extraction would have been immediately halted and the VR removed, but this was not the case for any patient in this study. Once the extraction had been performed, the VR was removed, hemostasis was confirmed, and the procedure was concluded.
VR presentation
The prototype VR software we used for this study was specially developed by the company PR NETWORK Co. (Fukuoka, Japan) for the purposes of relaxation. The author owns the copyright of this software. The presentation provided to the patients took account of the fact that patients were 5
unable to move their heads to follow the images with their gaze. Specifically, the VR reproduced a large film screen either in a cinema or set up outdoors (on a beach or in a garden), on which the images were projected (Figure. 1). Natural scenes of the sea or rivers, or animals exhibiting little movement, were projected onto the screen to produce a healing effect. The scenes shown on the screen were changed approximately every 3 min to avoid patients becoming bored with the images.
Statistical analysis
VAS anxiety scores were compared using Student’s t-test. Data were expressed as mean±SD. Values of p<0.05 were considered indicative of statistical significance. Statistical analysis was carried out using JMP® Pro12 (SAS Institute, Tokyo) for Windows.
Results
The extraction completion rate for patients wearing the VR device was 100%, with no extraction halted for any patient who used VR. One patient reported on the post-VR questionnaire symptoms similar to those of motion sickness, but no clinical signs were apparent.
Anxiety state
The mean difference in anxiety and fear evaluated by the VAS before and during treatment was – 13.3 ± 28.7 mm, suggesting alleviation of anxiety (n=51) (Figure. 2). Among patients in the VR group whose VAS score for pain while using VR was ≤10 (n=29), the difference in VAS scores before and during treatment was –21.6 ± 25.9 mm, an even greater reduction than for anxiety. In contrast, in the non-VR group (n=49), anxiety tended to increase, with a mean difference of 4.0 ±
6
22.3 mm. The difference between the two groups was significant (p=0.0014 and p=0.0001 respectively).
Questionnaire evaluations
In response to the questionnaire on the alleviation of fear and anxiety by VR use, 14% of patients said that it decreased greatly, 78% that it decreased, 8% that it was unchanged, 0% that it increased slightly, and 0% that it increased. Anxiety and fear were thus alleviated in 92% of patients (Table 3).
In response to the satisfaction questionnaire, 31% of patients said that they were satisfied, 51% were somewhat satisfied, 14% were neither satisfied nor dissatisfied, 4% were somewhat dissatisfied, and 0% were dissatisfied (Table 4).
HRV measurements
HRV measurements confirmed that the LF/HF ratio improved during VR use compared with before treatment (Figure. 3a).
HRV measurements also showed the sympathetic-nerve predominant state before treatment, with the value of LFnorm [LF/(LF + HF) × 100], the proportion accounted for by the sympathetic nervous system, at 70% and that of HFnorm [HF/(LF + HF) × 100], the proportion accounted for by the parasympathetic nervous system, at 30%. After VR use, however, LFnorm was 42% and HFnorm was 58%, indicating equilibrium with the parasympathetic nervous system (Figure. 3b).
Discussion
7
Many patients are frightened or anxious about surgery under local anesthesia1. Pain and fear that they have felt during previous dental treatment frequently become imprinted, and the pre-treatment questionnaire in the present study also suggested that most patients felt stressed before treatment. In OMS in particular, the face is usually covered with a cloth to keep operations hygienic, obscuring the patient’s view. The patients are required to keep their mouth open for long periods during treatment, and the metallic screech of the drill and the unpleasant smell generated by the drilling of hard tissue such as teeth and bone all contribute to raising their stress to an extremely high level. Even given adequate analgesia by local anesthesia, patients still experience mental and physical stress during treatment. In some cases this may lead to dental phobia1. The methods generally used to relieve this anxiety and fear of treatment include sedation by inhalation anesthesia or intravenous anesthesia, as well as the use of tranquillizers. However, drug administration may cause side effects or be contraindicated, and is thus not suitable for all patients. Many OMS procedures also require the use of irrigation, and a deeper the level of anesthesia corresponds to a higher the risk of aspiration or accidental ingestion.
A less invasive, safe, simple method of relieving fear and anxiety about surgical treatment is therefore still required15. Some past reports have described the use of VR to alleviate anxiety and fear related to some medical actions16-18. The results in the present study confirmed that anxiety and fear were alleviated in the majority of VR users. This effect was particularly pronounced in patients for whom pain was well controlled. HRV analysis, which makes use of small variations in heart rate, enables the visualization of stress effects including physical responses and fatigue, and provides a method of confirming patients’ state of health and psychophysiological stability11,12,19. The HRV results in the present study showed that, although patients were in an excited state before treatment, in the sympathetic-nerve predominant state, while they were experiencing the VR presentation, the 8
parasympathetic nervous activity became somewhat predominant, and the two were in balance, suggesting that they were approaching a stable mental state. We are aware that the number of patients included in HRV study is limited; however, it is difficult to create the environment for HRV analysis. HRV data are easily influenced by around circumference. Further studies with large populations should be done in order to validate our work.
Previous studies have also found that experiencing a VR presentation relieved pain during burn treatment20,21. The present results did not show any clear effect in terms of pain relief. It has been suggested that the effect on pain may be influenced by the content of presentation provided, and further investigations of the type of images presented may enable not only anxiety and fear but also pain to be controlled by VR22.
Generally speaking, VR presentations involving movement may produce symptoms similar to motion sickness. Care is required in the future to avoid cybersickness caused by experiencing such VR presentations23. Cybersickness is caused by a sense mismatch between visual perception and the muscles, inner ear, and other organs when the viewer’s gaze follows text or images moving rapidly on the screen, which results in headaches, nausea, and insecurity24,25. The images used in this study were chosen to include as little movement as possible, and this may have affected the results. The aim was also to use generally acceptable content, choosing natural scenes and images of animals exhibiting little movement. The majority of patients were able to concentrate on the images, but some responded that they were bored. This result may also have reflected the fact that the long treatment took approximately 30 minutes to complete, as well as individual differences in patients’ preferences.
9
Problems with VR use include the thickness of the head-mounted display, which impeded surgical treatment. Since it also imposes restrictions on the surgeons’ posture, the currently available display also limits the types of treatment that can be performed. At present, a certain height is required for the construction of three-dimensional images, and this is the same for all commercially available models. If a much thinner display could be worn, this would enable its use during almost all dental and surgical treatments. Device development is thus now required from the engineering viewpoint. A high proportion of young people today have experience with VR, and it holds the potential to become an easily acceptable medical assistive device in the future26. In the questionnaire after the use of VR, 100% of patients responded that they would want to use VR when undergoing further surgical treatment, and 96% responded that they would want to use VR when undergoing dental treatment in the future27,28. In the future, it could also be combined with augmented reality (AR), leading to the effective use of VR/AR in medicine29. Also further studies using near-infrared spectroscopy (NIRS) or dynamic magnetic resonance imaging (MRI) to measure changes in cerebral blood flow are required to ascertain the extent to which this effect can be achieved.
5.
Conclusion
In summary, our results showed that VR during mandibular impacted third molar extraction under local anesthesia effectively alleviated fear and anxiety during treatment. This study was limited to tooth extraction, but VR may also have some effect in relieving anxiety during other forms of dental treatment.
10
Author information
Author’s contributions:
YY designed the study. DS performed all surgical treatment. RA and KM contributed to the statistical analysis. All the authors interpreted data. YY wrote the manuscript, all authors reviewed the manuscript.
Competing Interests:
The authors declare no competing interests.
Funding:
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Acknowledgement
The author kindly appreciate the precious work of PR NETWORK Co. for VR production.
11
References : 1. Becker DE. Pain management: Part 1: Managing acute and postoperative dental pain. Anesth Prog
57: 67, 2010.
2. Matsumura K, Miura K, Takata Y, et al: Changes in blood pressure and heart rate variability during dental surgery. Am J Hypertens 11: 1376, 1998; 3. Momota Y, Tomioka S, Furukita M, et al: Adrenergic urticarial and glossalgia induced by stress during dental therapy and monitored by heart rate variability analysis. A case report. J Oral Maxillofac Surg Med Pathol 25: 264, 2013. 4. Johnston M, Carpenter L: Relationship between preoperative anxiety and postoperative state. Psychol Med 10: 361, 1980. 5. Calipel S, Lucas-Polomeni MM, Wodey E, et al: Premedication in children: hypnosis versus midazolam. Pediat Anesth 15: 275, 2005. 6. Melin-Aldana H, Sciortino D: Virtual reality demonstration of surgical specimens, including links to histologic features. Mod Pathol 16: 958, 2003. 7. Madrigal E, Prajapati S, Hernandez-Prera JC: Introducing a virtual reality experience in anatomic pathology education. Am J Clin Pathol 146: 462, 2016. 8. Abe T, Raison R, Shinohara N, et al: The effect of visual-spatial ability on the learning of robot-assisted surgical skills. J Surg Educ 75: 458, 2018. 9. Oing T, Prescott J: Implementations of virtual reality for anxiety-related disorders: Systematic review. JMIR Serious Games 6: e10965, 2018. 10. Tarrant J, Viczko J, Cope H: Virtual reality for anxiety reduction demonstrated by quantitative EEG: a pilot study. Front Psychol 9: Article 1280, 2018. 11. Malik M: Heart rate variability. Standards of measurement, physiological interpretation, and clinical use: Task Force of the European Society of Cardiology and the North America Society of Pacing and Electrophysiology. Circulation 93: 1043, 1996. 12. Malik M: Heart rate variability. Standards of measurement, physiological interpretation, and clinical use. Eur Heart J 17: 354, 1996. 13. Huang CJ, Kuok CH, Kuo TB, et al: Pre-operative measurement of heart rate variability predicts hypotension during general anesthesia. Acta Anaesthesiol Scand 50: 542, 2006. 14. Pell GJ, Gregory GT: Impacted mandibular third molars: Classification and modified techniques for removal. The Dental Digest 39: 330, 1933. 15. Saadat H, Drummond-Lewis J, Maranets I: Hypnosis reduces preoperative anxiety in adult patients. Anesth Analg 102: 1394, 2006.
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16. Ganry L, Hersant B, Sidahmed-Mezi M, et al: Using virtual reality to control preoperative anxiety in ambulatory surgery patients: A pilot study in maxillofacial and plastic surgery. J Stomatol Oral Maxillofac Surg 119: 257, 2018. 17. Maples-Keller JL, Yasinski C, Manjin N, et al: Virtual reality-enhanced extinction of phobias and post-traumatic stress. Neurotherapeutics 14: 554, 2017. 18. Shiban Y, Schelhorn I, Pauli P, et al: Effect of combined multiple contexts and multiple stimuli exposure in spider phobia: a randomized clinical trial in virtual reality. Behav Res Ther 71: 45, 2015. 19. Shim SH, Park S-Y, Moon SN, et al: Baseline heart rate variability in children and adolescents with vasovagal syncope. Korean J Pediatr 57: 193, 2014. 20. Hoffman HG, Doctor JN, Patterson DR, et al: Virtual reality as an adjunctive pain control during burn wound care in adolescent patients. Pain 85: 305, 2000. 21. Scapin S, Echevarria-Guanilo ME, Boeira Fuculo Junior PR, et al: Virtual reality in the treatment of burn patients: A systematic review. Burns 44: 1403, 2017. 22. Khadra C, Ballard A, Dery J, et al: Projector-based virtual reality dome environment for procedural pain and anxiety in young children with burn injuries: a pilot study. J Pain Res 11: 343, 2018. 23. Pot-Kolder R, Veling W, Counotte J, et al: Anexiety partially mediates cybersickness symptoms in immersive virtual reality environments. Cyberpsychol Behav Soc Netw 21: 187, 2018. 24. Weech S, Varghese JP, Barnett-Cowan M: Estimating the sensorimotor components of cybersickness. J Neurophysiol 120: 2201, 2018. 25. Mazloumi GA, Hodgson DM, Nalivaiko E: Effects of visual flow direction on signs and symptoms of cybersickness. PLoS One 12: e0182790, 2017. 26. Arane K, Behboudi A, Goldman RD: Virtual reality for pain and anxiety management in children. Can Fam Physician 63: 932, 2017. 27. Gujjar KR, van Wijk A, Kumar R, et al: Efficacy of virtual reality exposure therapy for the treatment of dental phobia in adults: A randomized controlled trial. J Anxiety Disord 62: 100, 2019. 28. Shetty V, Suresh LR, Hegde AM: Effect of virtual reality distraction on pain and anxiety during dental treatment in 5 to 8 year old children. J Clin Pediatr Dent 43: 97, 2019. 29. Tepper OM, Rudy HL, Lefkowitz A, et al: Mixed reality with HoloLens: Where virtual reality meets augmented reality in the operating room. Plast Reconstr Surg 140: 1066, 2017.
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Figure legends
Figure 1.
VR experience.
The experience reproduces a large screen set up in the center of an outdoor or indoor virtual space, on which images are shown.
Figure 2.
Changes in VAS anxiety scores.
Anxiety improved among patients who used VR (n=51), with a difference of –13.3 ± 28.7 mm in anxiety measured using a visual analog scale (VAS) between before and during treatment, whereas it increased by 4.0 ± 22.3 mm in patients who did not use VR (n=49). Among patients in the VR group whose VAS score for pain while using VR was ≤10 (n=29), the difference in VAS scores before and during treatment was –21.6 ± 25.9 mm, an even greater reduction than for anxiety. Graphs show statistical results of VAS anxiety scores (mean ± standard deviation) per group. P<0.05 in the VR group compared with the non-VR group by Student’s t-test.
Figure 3.
Changes in autonomic nervous system balance.
(a) The LF/HF ratio, which reflects autonomic nervous balance, improved during VR use compared with before treatment.
14
(b) Rates in percentages (LFnorm: percentage controlled by the sympathetic nervous system; HFnorm: percentage controlled by the parasympathetic nervous system).
The HRV results showed that, although patients were in the sympathetic-nerve predominant state (LFnorm 70% vs HFnorm 30%) before treatment, while they were experiencing the VR presentation, the parasympathetic nervous activity became predominant, and the two were in balance (LFnorm 42% vs HFnorm 58%). Values are the mean ± SD (n=8).
15
Tables
Table 1. Exclusion criteria.
(1)
Age <20 or ≥65 years
(2)
Pregnancy
(3) History of epilepsy (4) Heart disease (5) Dementia, mental retardation, mental illness, or similar condition (6) Claustrophobia (7) Currently undergoing treatment for dental phobia (8) Previous experience of feeling ill while using VR (cybersickness) or vertigo (9) Treatment requiring ≥ 1h
16
Table 2. Patient demographics.
VR
Gender
(%)
Female
24 (47.0)
36
(73.5)
Male
27
13
(26.5)
(53.0)
Age mean
27.6 ± 7.7
(range)
(20 - 47 ys)
35.0 ±11.8 (20 - 49 ys)
Data bare represented as a mean ± standard error of the mean. No significant differences were found between two groups (p>0.005).
17
Table 3. Response to the questionnaire on the alleviation of fear and anxiety by VR use.
Greatly decreased
Decreased
Unchanged
14%
78%
8%
Slightly increased 0%
Increased 0%
92% (n=51)
18
Table 4. Response to the satisfaction questionnaire by VR use.
Extremely satisfied
Somewhat satisfied
31%
51%
None of the above Somewhat dissatisfied
14%
Extremely dissatisfied
4%
0%
82% (n=51)
19
with VR (mm) 10
ALL
All
without VR Pain (-)
Pain (-)
0 -10 -20 -30 VAS (after) – VAS (before) -40 -50
(p=0.0014) (p=0.0001)
7
LF/HF Ratio
6 5 4 3 2 1 0
before treatment
During VR
90
Before treatment
During VR
80 70 60 50 40 30 20 10 0
LFnorm
HFnorm
LFnorm
HFnorm
S0278-2391(19)31343-6
DOI:
https://doi.org/10.1016/j.joms.2019.11.016
Reference:
YJOMS 58980
To appear in:
Journal of Oral and Maxillofacial Surgery
Received Date: 15 October 2019 Accepted Date: 7 November 2019
Please cite this article as: Yamashita Y, Shimohira D, Aijima R, Mori K, Danjo A, Clinical effect of virtual reality to relieve anxiety during impacted mandibular third molar extraction under local anesthesia, Journal of Oral and Maxillofacial Surgery (2019), doi: https://doi.org/10.1016/j.joms.2019.11.016. This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Published by Elsevier Inc on behalf of the American Association of Oral and Maxillofacial Surgeons
Clinical effect of virtual reality to relieve anxiety during impacted mandibular third molar extraction under local anesthesia
Yoshio Yamashita1, PhD, DDS; Daiji Shimohira2, PhD, DDS; Reona Aijima3, PhD, DDS; Kesuke Mori4, PhD, DDS; Atsushi Danjo5, PhD, DDS
1
Professor and Chief, Department of Oral and Maxillofacial Surgery, Faculty of Medicine,
Saga University 2-4
Research Associate, Department of Oral and Maxillofacial Surgery, Faculty of Medicine,
Saga University 5
Associate Professor, Department of Oral and Maxillofacial Surgery, Faculty of Medicine,
Saga University
Address correspondence to: Prof. Yoshio Yamashita, Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Saga University Nabeshima 5-1-1, Saga 849-8501, Japan Tel: 81-952-34-2397 Fax: 81-952-34-2044 E-mail: [email protected]
Abstract
Purpose: Many patients undergoing dental treatment have experienced pain associated with treatment, and they are anxious or fearful of treatment. Anxiety and fear have conventionally been dealt with by the use of inhalation anesthesia or tranquilizers, but their physical effects must also be considered, and they are not suitable for all patients. The purpose of this study was to assess the clinical effect of virtual reality (VR) to relieve anxiety during impacted mandibular third molar extraction under local anesthesia
Methods: We used VR to alleviate anxiety concerning surgical treatment in 51 patients undergoing impacted mandibular third molar extraction under local anesthesia. Fear and anxiety before and after treatment were evaluated by a questionnaire that included a visual analog scale (VAS). The post-treatment questionnaire asked patients to evaluate their satisfaction on a five level Likert scale. Heart rate variability (HRV) was also analyzed in the VR group using an acceleration plethysmograph (APG)
Results: Anxiety improved among patients who used VR (VR group), with a difference of –13.3 ± 28.7 mm in anxiety measured using a visual analog scale between before and during treatment, whereas it increased by 4.0 ± 22.3 mm in 49 patients who did not use VR. Furthermore, a post-treatment questionnaire using a five-point evaluation scale was administered to the VR group, and 92% reported that their anxiety had decreased. Objective evaluation by HRV measurement also showed a sympathetic nerve-predominant state before treatment, but during VR use during treatment, parasympathetic nervous activity was predominant, with a stable balance between the two. No patient showed symptoms suggestive of cybersickness.
1
Conclusions: These results demonstrate that VR may be valuable in dental treatment, particularly extractions, and surgical treatment.
Key words: Virtual Reality, Anxiety and Fear, Impacted Mandibular Third Molar Extraction, Heart Rate Variability
2
Introduction
The characteristic of orofacial pain is that it evokes subsequent fear and anxiety1. One of the best-known examples is dental treatment, which arouses anxiety and fear in many patients2,3. Analgesia with local anesthesia alone is insufficient to eliminate such anxiety and fear4. Sedation is frequently used for patients with dental phobia who are excessively anxious or frightened of treatment, involving intravenous anesthesia with propofol or a similar agent or inhalation anesthesia with nitrous oxide5. However, the use of drugs may involve restrictions on both patient and institution, and the scope for their use is limited.
Virtual reality (VR) refers to the techniques and systems used to create an environment by scientific and engineering techniques that is not itself a physical original but functions essentially in the same way by stimulating perception, including the user’s five senses. It consists of three elements: presence, autonomy, and interaction. It can therefore transport the user into a different experience by stimulating all the senses, not just sight. VR is already finding applications in a wide range of fields, and in medicine it is being put to use in areas including rehabilitation and medical education6,7. The use of VR for navigation in robot-assisted laparoscopic surgery has also recently been reported8. Studies have found that VR is effective for reducing pain and anxiety during surgical treatment9,10, but the details of this remain unclear. In this study, whether VR could be used to alleviate fear and anxiety while undergoing mandibular impacted third molar extraction under local anesthesia, the most common form of outpatient oral-maxillofacial surgery (OMS), was investigated.
Material and Methods
Study design 3
The study subjects were patients examined in the Department of Oral and Maxillofacial Surgery of Saga University Hospital in order to undergo mandibular impacted third molar extraction between April and November 2018. The patients were selected according to a number of criteria (Table 1). In particular, patients who suffered from motion sickness or claustrophobia and those with a history of cybersickness or vertigo were excluded from the study. The subjects were randomly divided into two groups, one that used VR (VR group) (n = 51 patients) and one that did not (non-VR group) (n = 49 patients). The characteristics of the patients in the two groups are shown in Table 2.
This study was approved by the Ethics Committee of the Faculty of Medicine of Saga University and was registered with UMIN Clinical Trials registry (UMIN000035594). Informed consent was obtained from all participants in this study. All methods were performed in accordance with relevant guidelines and regulations imposed by the IRB.
Subjective evaluation
Fear and anxiety before and after treatment were evaluated by a questionnaire that included a visual analog scale (VAS). Pain during treatment was also measured using a VAS. Anxiety was scored on a scale from “Completely relaxed” at 0 mm to “The most anxious state imaginable” at 100 mm. The post-treatment questionnaire asked patients to evaluate their satisfaction on a five level Likert scale with tooth extraction carried out while experiencing VR. They were also asked to evaluate the degree to which fear and anxiety were alleviated on a five-point scale. Other questions asked were whether they would want to use a VR device while undergoing further surgical treatment or during future dental treatment, and a section for free comments was also provided.
Objective evaluation 4
Heart rate variability (HRV) was also analyzed in 8 patients in the VR group using an acceleration plethysmograph (APG) (SA-3000Plus, TOKYOIKEN Co, Tokyo)11-13. The values measured in this study were the following: the low-frequency (LF) component (0.04–0.15 Hz), which reflects sympathetic and parasympathetic nervous activity; the high-frequency (HF) component (0.15–0.4 Hz), which reflects parasympathetic nervous activity; and LF/HF, which reflects autonomic nervous balance. These were measured twice, once before treatment and once 10 min after the start of the procedure. The measurement time was 3 min, and the patients were all placed in the supine position.
Surgical treatment
The impacted third molars were also horizontally impacted, corresponding to positions A and B and classes I and II in Pell and Gregory classification14.
After local infiltration anesthesia, patients
in the VR group were fitted with a biomonitor and a head-mounted display (OculusRift CV1, Oculus). Before the extraction was performed, they experienced a VR presentation for a short period and were asked to confirm that they were not feeling uncomfortable or disturbed. All extractions were carried out by a single specialist oral-maxillofacial surgeon. Had any patient been put off or made to feel uncomfortable by the VR, the extraction would have been immediately halted and the VR removed, but this was not the case for any patient in this study. Once the extraction had been performed, the VR was removed, hemostasis was confirmed, and the procedure was concluded.
VR presentation
The prototype VR software we used for this study was specially developed by the company PR NETWORK Co. (Fukuoka, Japan) for the purposes of relaxation. The author owns the copyright of this software. The presentation provided to the patients took account of the fact that patients were 5
unable to move their heads to follow the images with their gaze. Specifically, the VR reproduced a large film screen either in a cinema or set up outdoors (on a beach or in a garden), on which the images were projected (Figure. 1). Natural scenes of the sea or rivers, or animals exhibiting little movement, were projected onto the screen to produce a healing effect. The scenes shown on the screen were changed approximately every 3 min to avoid patients becoming bored with the images.
Statistical analysis
VAS anxiety scores were compared using Student’s t-test. Data were expressed as mean±SD. Values of p<0.05 were considered indicative of statistical significance. Statistical analysis was carried out using JMP® Pro12 (SAS Institute, Tokyo) for Windows.
Results
The extraction completion rate for patients wearing the VR device was 100%, with no extraction halted for any patient who used VR. One patient reported on the post-VR questionnaire symptoms similar to those of motion sickness, but no clinical signs were apparent.
Anxiety state
The mean difference in anxiety and fear evaluated by the VAS before and during treatment was – 13.3 ± 28.7 mm, suggesting alleviation of anxiety (n=51) (Figure. 2). Among patients in the VR group whose VAS score for pain while using VR was ≤10 (n=29), the difference in VAS scores before and during treatment was –21.6 ± 25.9 mm, an even greater reduction than for anxiety. In contrast, in the non-VR group (n=49), anxiety tended to increase, with a mean difference of 4.0 ±
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22.3 mm. The difference between the two groups was significant (p=0.0014 and p=0.0001 respectively).
Questionnaire evaluations
In response to the questionnaire on the alleviation of fear and anxiety by VR use, 14% of patients said that it decreased greatly, 78% that it decreased, 8% that it was unchanged, 0% that it increased slightly, and 0% that it increased. Anxiety and fear were thus alleviated in 92% of patients (Table 3).
In response to the satisfaction questionnaire, 31% of patients said that they were satisfied, 51% were somewhat satisfied, 14% were neither satisfied nor dissatisfied, 4% were somewhat dissatisfied, and 0% were dissatisfied (Table 4).
HRV measurements
HRV measurements confirmed that the LF/HF ratio improved during VR use compared with before treatment (Figure. 3a).
HRV measurements also showed the sympathetic-nerve predominant state before treatment, with the value of LFnorm [LF/(LF + HF) × 100], the proportion accounted for by the sympathetic nervous system, at 70% and that of HFnorm [HF/(LF + HF) × 100], the proportion accounted for by the parasympathetic nervous system, at 30%. After VR use, however, LFnorm was 42% and HFnorm was 58%, indicating equilibrium with the parasympathetic nervous system (Figure. 3b).
Discussion
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Many patients are frightened or anxious about surgery under local anesthesia1. Pain and fear that they have felt during previous dental treatment frequently become imprinted, and the pre-treatment questionnaire in the present study also suggested that most patients felt stressed before treatment. In OMS in particular, the face is usually covered with a cloth to keep operations hygienic, obscuring the patient’s view. The patients are required to keep their mouth open for long periods during treatment, and the metallic screech of the drill and the unpleasant smell generated by the drilling of hard tissue such as teeth and bone all contribute to raising their stress to an extremely high level. Even given adequate analgesia by local anesthesia, patients still experience mental and physical stress during treatment. In some cases this may lead to dental phobia1. The methods generally used to relieve this anxiety and fear of treatment include sedation by inhalation anesthesia or intravenous anesthesia, as well as the use of tranquillizers. However, drug administration may cause side effects or be contraindicated, and is thus not suitable for all patients. Many OMS procedures also require the use of irrigation, and a deeper the level of anesthesia corresponds to a higher the risk of aspiration or accidental ingestion.
A less invasive, safe, simple method of relieving fear and anxiety about surgical treatment is therefore still required15. Some past reports have described the use of VR to alleviate anxiety and fear related to some medical actions16-18. The results in the present study confirmed that anxiety and fear were alleviated in the majority of VR users. This effect was particularly pronounced in patients for whom pain was well controlled. HRV analysis, which makes use of small variations in heart rate, enables the visualization of stress effects including physical responses and fatigue, and provides a method of confirming patients’ state of health and psychophysiological stability11,12,19. The HRV results in the present study showed that, although patients were in an excited state before treatment, in the sympathetic-nerve predominant state, while they were experiencing the VR presentation, the 8
parasympathetic nervous activity became somewhat predominant, and the two were in balance, suggesting that they were approaching a stable mental state. We are aware that the number of patients included in HRV study is limited; however, it is difficult to create the environment for HRV analysis. HRV data are easily influenced by around circumference. Further studies with large populations should be done in order to validate our work.
Previous studies have also found that experiencing a VR presentation relieved pain during burn treatment20,21. The present results did not show any clear effect in terms of pain relief. It has been suggested that the effect on pain may be influenced by the content of presentation provided, and further investigations of the type of images presented may enable not only anxiety and fear but also pain to be controlled by VR22.
Generally speaking, VR presentations involving movement may produce symptoms similar to motion sickness. Care is required in the future to avoid cybersickness caused by experiencing such VR presentations23. Cybersickness is caused by a sense mismatch between visual perception and the muscles, inner ear, and other organs when the viewer’s gaze follows text or images moving rapidly on the screen, which results in headaches, nausea, and insecurity24,25. The images used in this study were chosen to include as little movement as possible, and this may have affected the results. The aim was also to use generally acceptable content, choosing natural scenes and images of animals exhibiting little movement. The majority of patients were able to concentrate on the images, but some responded that they were bored. This result may also have reflected the fact that the long treatment took approximately 30 minutes to complete, as well as individual differences in patients’ preferences.
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Problems with VR use include the thickness of the head-mounted display, which impeded surgical treatment. Since it also imposes restrictions on the surgeons’ posture, the currently available display also limits the types of treatment that can be performed. At present, a certain height is required for the construction of three-dimensional images, and this is the same for all commercially available models. If a much thinner display could be worn, this would enable its use during almost all dental and surgical treatments. Device development is thus now required from the engineering viewpoint. A high proportion of young people today have experience with VR, and it holds the potential to become an easily acceptable medical assistive device in the future26. In the questionnaire after the use of VR, 100% of patients responded that they would want to use VR when undergoing further surgical treatment, and 96% responded that they would want to use VR when undergoing dental treatment in the future27,28. In the future, it could also be combined with augmented reality (AR), leading to the effective use of VR/AR in medicine29. Also further studies using near-infrared spectroscopy (NIRS) or dynamic magnetic resonance imaging (MRI) to measure changes in cerebral blood flow are required to ascertain the extent to which this effect can be achieved.
5.
Conclusion
In summary, our results showed that VR during mandibular impacted third molar extraction under local anesthesia effectively alleviated fear and anxiety during treatment. This study was limited to tooth extraction, but VR may also have some effect in relieving anxiety during other forms of dental treatment.
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Author information
Author’s contributions:
YY designed the study. DS performed all surgical treatment. RA and KM contributed to the statistical analysis. All the authors interpreted data. YY wrote the manuscript, all authors reviewed the manuscript.
Competing Interests:
The authors declare no competing interests.
Funding:
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Acknowledgement
The author kindly appreciate the precious work of PR NETWORK Co. for VR production.
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57: 67, 2010.
2. Matsumura K, Miura K, Takata Y, et al: Changes in blood pressure and heart rate variability during dental surgery. Am J Hypertens 11: 1376, 1998; 3. Momota Y, Tomioka S, Furukita M, et al: Adrenergic urticarial and glossalgia induced by stress during dental therapy and monitored by heart rate variability analysis. A case report. J Oral Maxillofac Surg Med Pathol 25: 264, 2013. 4. Johnston M, Carpenter L: Relationship between preoperative anxiety and postoperative state. Psychol Med 10: 361, 1980. 5. Calipel S, Lucas-Polomeni MM, Wodey E, et al: Premedication in children: hypnosis versus midazolam. Pediat Anesth 15: 275, 2005. 6. Melin-Aldana H, Sciortino D: Virtual reality demonstration of surgical specimens, including links to histologic features. Mod Pathol 16: 958, 2003. 7. Madrigal E, Prajapati S, Hernandez-Prera JC: Introducing a virtual reality experience in anatomic pathology education. Am J Clin Pathol 146: 462, 2016. 8. Abe T, Raison R, Shinohara N, et al: The effect of visual-spatial ability on the learning of robot-assisted surgical skills. J Surg Educ 75: 458, 2018. 9. Oing T, Prescott J: Implementations of virtual reality for anxiety-related disorders: Systematic review. JMIR Serious Games 6: e10965, 2018. 10. Tarrant J, Viczko J, Cope H: Virtual reality for anxiety reduction demonstrated by quantitative EEG: a pilot study. Front Psychol 9: Article 1280, 2018. 11. Malik M: Heart rate variability. Standards of measurement, physiological interpretation, and clinical use: Task Force of the European Society of Cardiology and the North America Society of Pacing and Electrophysiology. Circulation 93: 1043, 1996. 12. Malik M: Heart rate variability. Standards of measurement, physiological interpretation, and clinical use. Eur Heart J 17: 354, 1996. 13. Huang CJ, Kuok CH, Kuo TB, et al: Pre-operative measurement of heart rate variability predicts hypotension during general anesthesia. Acta Anaesthesiol Scand 50: 542, 2006. 14. Pell GJ, Gregory GT: Impacted mandibular third molars: Classification and modified techniques for removal. The Dental Digest 39: 330, 1933. 15. Saadat H, Drummond-Lewis J, Maranets I: Hypnosis reduces preoperative anxiety in adult patients. Anesth Analg 102: 1394, 2006.
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16. Ganry L, Hersant B, Sidahmed-Mezi M, et al: Using virtual reality to control preoperative anxiety in ambulatory surgery patients: A pilot study in maxillofacial and plastic surgery. J Stomatol Oral Maxillofac Surg 119: 257, 2018. 17. Maples-Keller JL, Yasinski C, Manjin N, et al: Virtual reality-enhanced extinction of phobias and post-traumatic stress. Neurotherapeutics 14: 554, 2017. 18. Shiban Y, Schelhorn I, Pauli P, et al: Effect of combined multiple contexts and multiple stimuli exposure in spider phobia: a randomized clinical trial in virtual reality. Behav Res Ther 71: 45, 2015. 19. Shim SH, Park S-Y, Moon SN, et al: Baseline heart rate variability in children and adolescents with vasovagal syncope. Korean J Pediatr 57: 193, 2014. 20. Hoffman HG, Doctor JN, Patterson DR, et al: Virtual reality as an adjunctive pain control during burn wound care in adolescent patients. Pain 85: 305, 2000. 21. Scapin S, Echevarria-Guanilo ME, Boeira Fuculo Junior PR, et al: Virtual reality in the treatment of burn patients: A systematic review. Burns 44: 1403, 2017. 22. Khadra C, Ballard A, Dery J, et al: Projector-based virtual reality dome environment for procedural pain and anxiety in young children with burn injuries: a pilot study. J Pain Res 11: 343, 2018. 23. Pot-Kolder R, Veling W, Counotte J, et al: Anexiety partially mediates cybersickness symptoms in immersive virtual reality environments. Cyberpsychol Behav Soc Netw 21: 187, 2018. 24. Weech S, Varghese JP, Barnett-Cowan M: Estimating the sensorimotor components of cybersickness. J Neurophysiol 120: 2201, 2018. 25. Mazloumi GA, Hodgson DM, Nalivaiko E: Effects of visual flow direction on signs and symptoms of cybersickness. PLoS One 12: e0182790, 2017. 26. Arane K, Behboudi A, Goldman RD: Virtual reality for pain and anxiety management in children. Can Fam Physician 63: 932, 2017. 27. Gujjar KR, van Wijk A, Kumar R, et al: Efficacy of virtual reality exposure therapy for the treatment of dental phobia in adults: A randomized controlled trial. J Anxiety Disord 62: 100, 2019. 28. Shetty V, Suresh LR, Hegde AM: Effect of virtual reality distraction on pain and anxiety during dental treatment in 5 to 8 year old children. J Clin Pediatr Dent 43: 97, 2019. 29. Tepper OM, Rudy HL, Lefkowitz A, et al: Mixed reality with HoloLens: Where virtual reality meets augmented reality in the operating room. Plast Reconstr Surg 140: 1066, 2017.
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Figure legends
Figure 1.
VR experience.
The experience reproduces a large screen set up in the center of an outdoor or indoor virtual space, on which images are shown.
Figure 2.
Changes in VAS anxiety scores.
Anxiety improved among patients who used VR (n=51), with a difference of –13.3 ± 28.7 mm in anxiety measured using a visual analog scale (VAS) between before and during treatment, whereas it increased by 4.0 ± 22.3 mm in patients who did not use VR (n=49). Among patients in the VR group whose VAS score for pain while using VR was ≤10 (n=29), the difference in VAS scores before and during treatment was –21.6 ± 25.9 mm, an even greater reduction than for anxiety. Graphs show statistical results of VAS anxiety scores (mean ± standard deviation) per group. P<0.05 in the VR group compared with the non-VR group by Student’s t-test.
Figure 3.
Changes in autonomic nervous system balance.
(a) The LF/HF ratio, which reflects autonomic nervous balance, improved during VR use compared with before treatment.
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(b) Rates in percentages (LFnorm: percentage controlled by the sympathetic nervous system; HFnorm: percentage controlled by the parasympathetic nervous system).
The HRV results showed that, although patients were in the sympathetic-nerve predominant state (LFnorm 70% vs HFnorm 30%) before treatment, while they were experiencing the VR presentation, the parasympathetic nervous activity became predominant, and the two were in balance (LFnorm 42% vs HFnorm 58%). Values are the mean ± SD (n=8).
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Tables
Table 1. Exclusion criteria.
(1)
Age <20 or ≥65 years
(2)
Pregnancy
(3) History of epilepsy (4) Heart disease (5) Dementia, mental retardation, mental illness, or similar condition (6) Claustrophobia (7) Currently undergoing treatment for dental phobia (8) Previous experience of feeling ill while using VR (cybersickness) or vertigo (9) Treatment requiring ≥ 1h
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Table 2. Patient demographics.
VR
Gender
(%)
Female
24 (47.0)
36
(73.5)
Male
27
13
(26.5)
(53.0)
Age mean
27.6 ± 7.7
(range)
(20 - 47 ys)
35.0 ±11.8 (20 - 49 ys)
Data bare represented as a mean ± standard error of the mean. No significant differences were found between two groups (p>0.005).
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Table 3. Response to the questionnaire on the alleviation of fear and anxiety by VR use.
Greatly decreased
Decreased
Unchanged
14%
78%
8%
Slightly increased 0%
Increased 0%
92% (n=51)
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Table 4. Response to the satisfaction questionnaire by VR use.
Extremely satisfied
Somewhat satisfied
31%
51%
None of the above Somewhat dissatisfied
14%
Extremely dissatisfied
4%
0%
82% (n=51)
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with VR (mm) 10
ALL
All
without VR Pain (-)
Pain (-)
0 -10 -20 -30 VAS (after) – VAS (before) -40 -50
(p=0.0014) (p=0.0001)
7
LF/HF Ratio
6 5 4 3 2 1 0
before treatment
During VR
90
Before treatment
During VR
80 70 60 50 40 30 20 10 0
LFnorm
HFnorm
LFnorm
HFnorm